With the development of modern wireless communication technology, the microwave radio frequency (RF) systems are required to develop toward higher frequency, higher speed and wider frequency bands. Therefore, as the core component of the microwave RF systems, the monolithic microwave integrated circuit (MMIC) and its packaging technology are also face new challenges. An ideal MMIC package not only requires a strong mechanical structure to protect the circuit from exposure to the external environment, but also ensures the integrity of microwave signal and electrical signal. For high-power MMICs, the package requires good heat dissipation potential.
The RF performance of the traditional ceramic quad flat non-leaded package does not completely cover the X-band, and the return loss deteriorates rapidly with the frequency, and it is difficult to eliminate the in-band resonance point. In addition, this structural package has very narrow ceramic wall, and can only be sealed with alloy solder seal method. Moreover, this sealing method is complicated, and the cost is high, which leads to high cost of the integrated circuit, and which is not conducive to the continuous reduction of the cost of the ceramic package.